The present invention relates to a bill counting machine, and more particularly to a bill counting machine in which bills are counted while detecting the presence of bills of different kinds or denominations mixed in by reading out the optical pattern of the bill surfaces.
The general functions of a bill counting machine are that of counting the number of bills by absorbing and turning over bills one by one by means of the negative pressure of suction heads that rotate while revolving and that of checking for the presence of bills whose denominations are different from that of the bills being counted.
In a conventional bill counting machine, the bills of different denominations are discriminated mainly by differences in their external dimensions. According to this method, however, it is impossible to discriminate between the obverse and reverse sides of bills. Therefore, it is not possible to meet the need to properly arrange the obverse or reverse sides of bills contained in a bundle of bills. At the same time, this method has another disadvantage in that, in the case of various denominations of bills whose dimensions are identical as in the case of U.S. bills, it is impossible to discriminate the presence of bills of different denominations.
Another conventional method of discrimination is that used in the "bill counting machine" disclosed in Japanese Pat. No. 1167062. According to this "bill counting machine," the pattern of a specific spot on a bill is optically read out so as to discriminate between the obverse and reverse sides.
In this method of discrimination, however, measurement errors are liable to occur due to the stains on and creases in the bills. Furthermore, such a method has a drawback in that in cases where the designs of various denominations of bills are similar as in the case of U.S. bills, it is difficult to discriminate between various types of bills.